Study will look at the efficacy of doxycycline in stopping breakthrough menstrual bleeding in women on continuous hormonal birth control

Women taking part in a new drug trial under way at the University of Hawaiʻi at Mānoa can receive free birth control pills along with a check-up and a gift card.

The study at the UH Mānoa John A. Burns School of Medicine looks to evaluate a very low dose of the medication doxycycline, a common antibiotic used to treat conditions like acne. Researchers hope that the low dose of doxycycline will prevent breakthrough menstrual bleeding in women who use continuous birth control pills. All participants in the study will take a continuous birth control pill. Participants will also take a second medication, either a low dose of doxycycline or a placebo pill.

Taking a continuous birth control pill means that women take hormonally active pills everyday and skip the "placebo week" so that they do not have a period. Taking pills in this way is medically safe and was initially done for women with menstrual-related problems like endometriosis or menstrual headaches.

"If the study shows the drug is successful in stopping ʻbreakthrough bleeding,ʻ more women may turn to new continuous contraceptive options—options that allow women to effectively stop menstrual bleeding," said study investigator Bliss Kaneshiro, M.D.

"Not having a menstrual period is a great option for many women, especially women who are active, have painful periods or just find that having a period is a nuisance," said Dr. Kaneshiro. "However, one of the downsides of starting a continuous method is the unscheduled, breakthrough bleeding that women experience in the first few months of use. Thatʻs what the clinical trial seeks to address."

To Honolulu women like Christine Vo, continual hormonal contraception without breakthrough bleeding is an attractive option. "Sometimes a womanʻs period is too long, too heavy, or itʻs uncomfortable to wear a tampon or pad," said Vo. "I think a lot of women would choose not to have their period as long as it was safe."

Ronnie Texeira, another Honolulu woman participating in the trial, says itʻs especially useful for Hawaiʻi women to take part in medical studies like this one. "A lot of medical trials are done on white populations only, or among whites and blacks, but they donʻt include a lot of different ethnicities. In Hawaiʻi, our diverse population is a definite plus in making sure our research is inclusive."

Vo and Texeira are currently taking a continuous birth control pill, the first FDA-approved continuous oral contraceptive. As part of the study, the women keep a journal to enter details of any menstrual bleeding.

Dr. Kaneshiro has been involved in a similar trial at Oregon Health Sciences University, where she worked before returning home to Hawaiʻi. She is excited to bring both her skills as an obstetrician-gynecologist and researcher home to the Islands.

"Taking a birth control pill that eliminates a menstrual period will not appeal to all women, but for many women, it will be an attractive contraceptive choice that fits with their lifestyle," said Dr. Kaneshiro.

Women 18 years or older who are interested in learning more or participating in this study should contact the University of Hawaiʻi Clinical Research Center at (808) 983-6243 or email doxy@crc.Hawaiʻi.edu.